As in MULTi-GPU and NOT SLI or Crossfire.
Hopefully there are other enthusiasts here and we can exchange findings, tips, and tricks
I’ll start off with some comments:
Heterogenous mGPU would be games such as mGPU titles such as Ashes of the singularity, Strange Brigade, Civilization 6, Zombie Army 4, Total War I and II, Gears of War, the firts release of Quake II RTX , and such benchmarks as Tellusim’s GravityMark
Again, we are not discussing SLI or Crossfire
Example, there is no SLI here and not using NVLINK
I’ve been testing some UE5 titles and the findings are consistent. UE5 titles can also apply mGPU to path tracing as well with engine 5.1, 5.2, 5.3 and 5.4
Other titles are Hellblade 2, Silent Hill 2, and the Talos Principle 2, as just a few examples.
I have also found that some UE4 titles allow for mGPU
For the Matrix Awakens City Demo UE5, 5.2 and 5.3, I almost scale to double the performance using the second card , however moving to same demo in UE5 5.4 the performance increase for the second video card is only 45%.
Again, everything is et to max textures, max eye candy, max ray tracing, etc and all at least at 4K without using DLSS or FG
so… milage may vary with development.
some tips and tricks include:
-d3d12 -MaxGPUCount=2
r.PathTracing.GPUCount 2
-game -d3d12 -MaxGPUCount=2
D3D12.AFRSyncTemporalResources=1
D3D12.AFRUseFramePacing=1
r.GPUParticle.AFRReinject=1
r.AllowMultiGPUInEditor=1
r.EnableMultiGPUForkAndJoin=1
r.PathTracing.GPUCount 4
also. it depends on the kind of developer, savviness, what was scrapped before release, what was made into it but not documented, etc. etc etc
Please optimize and enable Resizable BAR to “unlimited” and if you are using nVidia drivers you may want to turn OFF shader cache.
Allow me to qualify the observation:
This is done at MAX eye candy in 4K or 8K.
in situations of “high demand” and “higher resolution” with MAX ray tracing, max eye candy, but when NOT using visual gimmicks such as DLSS (mostly resolution reduction) or FG
This also observed in situations where higher rez textures are used (4k, 8k, etc) with or accompanied with max eye candy
max eye candy, to me, means: No DLSS, No FG, No Vignetting, no noise, no Film Grain, 4k (or above) and using 120hs + monitor and HDMI 2.1 or DP 1.4
4K or 8K and no resolution reduction gimmicks… you heard me… gimmicks! Why buy an expensive monitor just to run at half the resolution?! DLSS, FG. and FSR are just lower resolutions offered so that you can buy an expensive video card that can’t run the game at 4k with max eye candy and Ray Tracing set to ULTRA or path tracing set to Ultra, EPIC or Cinematic.
That is when, to get4k MAX eye candy, NO DLSS, NO FG, and NO FSR requires…a second identical video card (if you can get the title to work with it)
definitely not as simple as it sounds. It requires research, and a degree of dark arts and some Voodoo (yes that was a pun in reference to the SLI original cards… ok, I’ll stop)
Lets use an example that allows for disclosing the settings used, so that folks can see the end result:
I will use Chernobylite a UE4 title as a representative as the benchmark summary screen actually lists the setting used in the benchmark (wish more titles did this)
Again, max eye candy, to me, means: No DLSS, No FG, No Vignetting, no noise, no Film Grain, 4k (or above) and using 120hs + monitor and HDMI 2.1 or DP 1.4
1 GPU Chernobylite MAX settings all with Raytracing set to ultra, 4K, NO DLSS and NO FG
2GPU Chernobylite MAX settings all with Raytracing set to ultra, 4K, NO DLSS and NO FG
In this example, FPS went from an average of 127 FPS to an average of 228 FPS
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228 FPS with Ray Tracing set to ULTRA and no DLSS ! This why one should understand mGPU.
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So if you are interested, let us contribute. We can get down to the minute details of how and exchange ideas.
If you have never done Multi GPU (non sli or crossfire) start off with identical cards and try GravityMark and or Ashes of the Singularity
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For some apps or games setting up mGPU is available through the interface complete with choices and selections, ithers is just a check mark and for some others its only possible with xml, ini, and cfg changes as well as launch parameters,
Gravity Mark interface:
Ashes of the Singularity interface:
Civilization IV
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So while this a gaming discussion, this particular PC build was actually designed for medical imaging and CNN / RCNN, but since its my personal home PC it does do other things, including gaming.
I actively participate on Ai / algorithm groups and forums, and that has its own common language. Here, that would be non sequitur, so while gaming is not its primary focus, in this forum gaming is more of a common language.
So for gaming, I’m more of a non-steam, not a rent to play kinda guy. I like to own my games (and music, and videos etc). So I have a lot of boxes/classics. I like clicking on one exe without additional clients, telemetry, and forced updates etc.
If I must have a recent title and I can’t get it as a “standalone” then I may buy the game, but play using a crack.
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My PC - (primary test system) The Zen of Air Cooling
2x 4090 RTX Founders Edition
2x AMD Epyc 9684X (192/384 cores) 2.2GB of cache , Gigabyte MZ73-LM0 Dual socket motherboard, PCIE 5.0
1.5 TB RAM DDR5 ECC LRDIMMs 4800mhz 2050W digital power supply
4x Micron 9300 Max (15.4TB each) Sabrent Rocket 4 Plus (8TB). 2x Back up drives Micron 5300
Asus PA32UCG-K monitor, MS Data Center 2022 & Ubuntu, and MS Data Center 2025 (preview)
Second test system:
2x 3090 Ti Founders Edition (with NvLink bridge)
2x AMD Epyc 7773X (128/256 cores) 1.5GB cache of cache, Gigabyte MZ72-HB0 dual Socket motherboard
1.0 TB RAM DDR4 ECC LRDIMMS, 2050w power supply
5x Micron 9300 Max (15.4TB each 64TB RAID, Overprovisioned) Sabrent Rocket 4 Plus (8TB). 2x Back up drives Micron 5300
Asus PA32UCG-K monitor, MS Data Center 2022 & Ubuntu, and MS Data Center 2025 (preview)